1. Field of the Invention
The present invention relates to connectors for automatically making a mechanical or electrical and mechanical connection to an inserted cable end using the wedge action of tapered jaws. More particularly, the invention relates to an automatic cable connector using the impact of a hammer for closing the cable gripping jaws.
2. Background of the Invention
A typical automatic cable connector includes a tubular housing with an open end into which a cable end is received. The housing includes a tapered surface that cooperates with tapered jaw segments. A spring continually biases the jaw segments toward the tapered surface. When a cable end is inserted, it moves the jaws away from the tapered surface against the bias of the spring, permitting the cable to pass between the jaws. After the cable is inserted, the spring biases the jaw segments into engagement with the tapered surface. When the cable is then subjected to tension, the jaws are pulled against the tapered surface to firmly grip the cable. Examples of this known type of automatic cable connector are the STRANDVISE cable termination connectors and STRANDLINK cable splice connectors of Reliable Power Products, Inc. shown in a brochure entitled "Wirelink, Wirevise, Strandlink Strandvise" published prior to the present invention.
The conventional arrangement works well in those installations where the cable is subjected to substantial tension after insertion into the cable connector. However, there are applications, such as slack span installations, where the cable is subjected to little or no tension. In this case, the cable tension does not always provide the force necessary to create a sufficient jaw gripping reaction against the tapered surface of the housing. Although an installer can apply tension to the cable during installation for the specific purpose of generating the jaw gripping force, the resulting jaw grip effectiveness depends on consistent and proper installation techniques.
In order to overcome this problem, it has been proposed to rely on the force of a strong jaw biasing spring instead of wire tension to provide the jaw gripping force. When this approach is employed, if the jaws are continuously biased by the spring, the large spring force makes it difficult to insert a cable end between the jaw segments. Accordingly, known connectors of this type include a mechanism for holding the spring in a compressed state, away from the jaw segments, until a cable end is inserted and for releasing the spring to contact the jaw segments after the cable end is inserted.
U.S. Pat. No. 2,077,737 discloses cable joints with spring biased wedges reacting against tapered surfaces to grip inserted cable ends. The spring is compressed during assembly, and is held in the compressed state by lock pins or pivoted dogs. When a cable end is inserted through the wedges, it releases the pins or dogs to release the spring. The spring biases the wedges toward the tapered surfaces.
U.S. Pat. No. 2,554,387 discloses a wire grip in which the jaws initially are not biased to a wire gripping position. A spring is compressed when the device is assembled and is held by a trigger. When a wire is inserted completely through the jaws, it engages and releases the trigger, freeing the spring to bias the jaws against a tapered surface so that the jaws grip the wire.
U.S. Pat. No. 4,362,352 discloses splicing devices with spaced apart cable gripping members driven into tapered surfaces by the force of a massive spring having an at rest length substantially longer than the space between the gripping members- The spring is compressed when the device is assembled and before a cable is inserted. After the cable is inserted, the spring is released by cutting a cord (FIGS. 1 and 4), disconnecting (FIG. 2) or severing (FIG. 3) a rod, or severing a retaining washer (FIG. 5).